Broadcast channels generally include advertisements for revenue. The viewers, however, may switch to a different channel to avoid the advertisements. In some broadcasting channels, an indication of the duration to the end of a current advertisement session is added to advertisements as an overlay. This indication is assumed to cause the viewers to continue viewing the channel since the time to the end of the advertisement session is known.
U.S. Patent Publication 2002/0178278 to Ducharme, describes receiving a plurality of channels, decoding all of them, inserting graphic overlays on some of the channels as required and re-encoding the channel.
U.S. Pat. No. 8,752,113 to Good describes insertion of graphic overlays after a transc der scale down function for achieving better video quality.
Another method for inserting graphic overlays is by sending the over content separately to a client device, as described by Smolic, U.S. Patent Publication No. 2015/0135212. Although this method eliminates the need to insert the ever-changing promotional overlays, it relies on advanced client devices to do the job and on non-standard distribution protocols.
In some cases, advertisements are personalized separately for each user or for relatively small groups of users. In such cases, the cost of adding overlay indications may be very high and therefore such overlay indications are usually not used with personalized advertisements.